Diphosphines containing silane groups, immobilise diphosphines and the use thereof as hydrogenation catalysts

ABSTRACT

Compounds of formula II ##STR1## wherein the groups (R 1 ) 2  P(CH 2 ) m  and n are in o- or m-position to each other and the substituents R 1  are identical or different radicals, m and n are each independently of the other 0 or 1, R 1  is linear or branched C 1  -C 12  alkyl, unsubstituted C 5  -C 6  cycloalkyl or C 5  -C 6  cycloalkyl which is substituted by C 1  -C 4  alkyl or C 1  -C 4  alkoxy, or is phenyl or benzyl, or both substituents R 1  in a group (R 1 ) 2  P together are o,o&#39;-diphenylene, --R 2  --X-- is a bond or --(C x  H 2x  --O) y  --, or X-- is O-- and R 2  is C 1  -C 6  alkylene, x is an integer from 2 to 6 and y is an integer from 2 to 6, R 3  is C 2  -C 18  alkylene, phenylene or benzylene, and R 4  is C 1  -C 6  alkyl or phenyl, can be applied to solid carriers, such as silica gel or aerosils, and complexed with rhodium or iridium compounds. These materials are heterogeneous and separable catalysts for the asymmetrical hydrogenation of prochiral compounds containing carbon double bonds or carbon/hetero atom double bonds, for example ketones and imines.

The present invention relates to pyrrolidine diphosphines which containsilane groups, to said pyrrolidine diphosphines fixed on a solid carriermaterial and to the use thereof in the form of rhodium or iridiumcomplexes for the hydrogenation of olefinic double bonds and heterodouble bonds, especially for enantioselective hydrogenation using chiralpyrrolidine diphosphines.

The enantioselective hydrogenation of ketimines to optically activesecondary amines using chiral rhodium and iridium diphosphine complexesas homogeneous catalysts is described in EP-A-0 256 982, EP-A-0 302 021and EP-A-0 301 457. The expensive catalysts cannot, however, berecovered, or recovery is only possible by complicated separatingmethods and always with unwanted losses. Moreover, these catalysts losemuch of their activity in the course of the first reaction, so thattheir direct reuse in further hydrogenation processes is allied to highlosses of yield and is therefore uneconomic. There is a need forcatalysts which can be readily separated and reused while substantiallyretaining their activity and, in particular, their selectivity.

In J. Chem. Japan. Soc., Chemistry Letters, pages 905 to 908 (1978), K.Achiwa describes polystyrene copolymers whose benzene rings containpyrrolidine diphosphine-N-carbonyl groups complexed with rhodium. It isdifficult to synthesize these monomers, and the hydrogenation ofprochiral olefins with these heterogeneous catalysts entails a loss ofenantioselectivity.

U. Nagel et al. disclose heterogeneous rhodium catalysts for theenantioselective hydrogenation of α-(acetylamino)cinnamic acid in J.Chem. Soc., Chem. Commun., pages 1098-1099. The catalysts arepyrrolidine diphosphines which are complexed with rhodium and whichcarry a triethoxysilyl-n-propyldicarboxylic acid monoamide radical atthe N-atom. They are applied to silica gel as solid carrier material.The synthesis of these materials is very troublesome. Althoughcomparably good selectivities are obtained as compared with themonomers, the loss of activity is high and diminishes the possibility ofreuse.

In one of its aspects the invention relates to compounds of formula I##STR2## wherein the groups (R₁)₂ P(CH₂)_(m) and n are in o- orm-position to each other and the substituents R₁ are identical ordifferent radicals, m and n are each independently of the other 0 or 1,R₁ is linear or branched C₁ -C₁₂ alkyl, unsubstituted C₅ -C₆ cycloalkylor C₅ -C₆ cycloalkyl which is substituted by C₁ -C₄ alkyl or C₁ -C₄alkoxy, or is phenyl or benzyl, or both substituents R₁ in a group (R₁)₂P together are o,o'-diphenylene, --R₂ --X-- is a bond or --(C_(x) H_(2x)--O)_(y) --, or X-- is O-- and R₂ is C₁ -C₆ alkylene, x is an integerfrom 2 to 6 and y is an integer from 2 to 6, R₃ is C₂ -C₁₈ alkylene,phenylene or benzylene, and R₄ is C₁ -C₆ alkyl or phenyl.

In the compounds of formula I, the sum of m+n is preferably 0 or 1.

The substituents R₁ of a phosphine group are preferably identicalradicals and, most preferably, all four substituents R₁ are identicalradicals.

R₁ as alkyl contains preferably 1 to 8, most preferably 1 to 4, carbonatoms. Alkyl is typically methyl, ethyl and the isomers of propyl,butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl.Particularly suitable alkyl and alkoxy substituents are methyl, ethyl,methoxy and ethoxy. Cycloalkyl is typically cyclopentyl and cyclohexyl.In a particularly preferred embodiment of the invention, R₁ is phenyl.

In another preferred embodiment of the invention, --R₂ --X-- is a bond.

R₂ as alkylene may be linear or branched and contains preferably 2 to 4and, most preferably, 2 or 3 carbon atoms. Illustrative examples aremethylene, ethylene, 1,2- and 1,3-propylene, 1,2-, 1,3-and 1,4-butylen,pentylene and hexylene. Particularly preferred alkylene radicals areethylene and 1,2-propylene.

In the group --(C_(x) H_(2x) --O)_(y) --, x is preferably 2, 3 or 4 and,most preferably, 2 or 3, and y is preferably an integer from 2 to 4.This group will typically be polyoxaethylene containing conveniently 2,3, 4, 5 or 6 oxaethylene units, or poly-1,2-oxapropylene containing 2,3, 4, 5 or 6 1,2-oxapropylene units.

R₃ as alkylene may be linear or branched and contains preferably 2 to 12carbon atoms. Illustrative examples are ethylene and the isomers ofpropylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene,decylene, undecyclene, dodecylene, tridecylene, tetradecylene,hexadecylene and octadecyclene. Preferably R₃ is linear or branchedalkylene of 3 to 12 carbon atoms, typically 1,3-propylene or1,11-undecyclene. In another embodiment, R₃ is preferably phenylene.

R₄ is preferably C₁ -C₄ alkyl and, most preferably methyl or ethyl.

The compounds of formula I are preferably obtained in the form of theoptically active isomers, with respect to the position of thephosphine(methyl) groups.

In a particularly preferred embodiment of the invention, R₁ is phenyland --R₂ X-- is a bond, R₃ is 1,3-propylene and R₄ is methyl or ethyl,and m is 1 and n is 0, and the groups (R₁)₂ P-- and (R₁)₂ PCH₂ -- are inm-position, or m and n are each 0 and the groups (R₁)₂ P-- are ino-position.

In another of its aspects, the invention relates to a process for thepreparation of compounds of formula I, which comprises reacting acompound of formula II

    (R.sub.4 O).sub.3 Si--R.sub.3 --NCO                        (II),

wherein R₃ and R₄ are as previously defined, with a compound of formulaIII ##STR3## wherein R₁, R₂, X, m and n are as previously defined.

The compounds of formula II are known and some are commerciallyavailable, or they can be prepared by a process described in FR-A-1 371405. The compounds of formula III, wherein --R₂ --X-- is a bond are alsoknown or can be prepared by known processes. Such processes aredescribed, for example, by U. Nagel in Angew. Chem., 96(6), pages425-426 (1984) and K. Achiwa, J. Amer. Chem. Soc., 98(25), pages8265-8266 (1976).

Compounds of formula III, wherein --R₂ --X-- is the group --(C_(x)H_(2x) --O)_(y) --, are novel and can be obtained in simple manner byreacting the substituted pyrrolidines with oxiranes. Compounds offormula III, wherein X is --O--, and R₂ is alkylene, can be obtained byreacting the pyrrolidines with appropriate halogenated alcohols or withone equivalent of oxirane.

The reaction of the isocyanates of formula II with the compounds offormula III can be carried out at room temperature or elevatedtemperature, as in the range from 0° to 100° C. The concurrent use of asolvent is expedient, for example a hydrocarbon (petroleum ether,pentane, hexane, cyclohexane, methyl cyclohexane, benzene, toluene orxylene), or a halogenated hydrocarbon (methylene chloride, chloroform,1,1,2,2-tetrachloroethane and chlorobenzene). The reaction of thehydroxyl group containing compounds of formula III is convenientlycarried out in the presence of a catalyst, such as a tin compound or atertiary organic amine. An excess of isocyanate can be removed after thereaction by the reaction with an alkanol. The isolation and purificationof the inventive compounds can be effected by conventional methods, asby distillation or chromatographic methods.

The inventive compounds are normally oily liquids which can be used aschiral ligands for iridium (I) and rhodium (I) complex salts which areexcellent homogeneous enantioselective hydrogenation catalysts. Thepreparation of such catalysts is disclosed, inter alia, in EP-A-0 256982. The inventive compounds are particularly suitable for preparingheterogeneous and enantioselective hydrogenation catalysts by fixingsaid compounds on a solid carrier material.

The invention further relates to a solid carrier material which containsdiphosphine rhodium or iridium complexes fixed on the surface thereof,which carrier material has the formula IV or IVa ##STR4## wherein Ydenotes two monoolefin ligands or a diene ligand, M is Ir(I) or Rh(I), Zis --Cl, --Br or --I, A.sup.⊖ is the anion of an oxyacid or complexacid, T is a solid carrier material, r is 0, 1 or 2, and R₁, R₂, R₃, R₄,X, m and n are as previously defined. R₁, R₂, R₃, R₄, X, m and n havethe same preferred meanings as given for the compounds of formula I.

A monoolefin ligand Y contains preferably 2 to 6, most preferably 2 to4, carbon atoms. Illustrative examples are hexene, pentene, butene,propene and, preferably, ethene. A diene ligand Y contains preferably 4to 8, most preferably 6 to 8, carbon atoms. The dienes may be open-chainor cyclic dienes whose olefin groups are preferably linked through oneor two carbon atoms. Preferred dienes are 1,5-hexadiene,1,5-cycloactadiene and norbornadiene.

Z in formula IV is preferably --Cl or --Br. A.sup.⊖ in formula IVa ispreferably ClO₄.sup.⊖, CF₃ SO₃.sup.⊖, BF₄.sup.⊖, B(phenyl)₄.sup.⊖,PF₆.sup.⊖, SbCl₆.sup.⊖, AsF₆.sup.⊖ or SbF₆.sup.⊖.

The solid carrier material is preferably selected from silicates andsemimetals or metal oxides as well as glasses which are most preferablyin the form of powders having average particle diameters of 10 nm to2000 μm, preferably 10 nm to 1000 μm and, most preferably, 10 nm to 500μm. The particles may be compact as well as porous particles. Porousparticles preferably have high inner surface areas, typically 1 to 1200m², preferably 30 to 600 m². Exemplary of oxides and silicates are SiO₂,TiO₂, ZrO₂, MgO, NiO, WO₃, Al₂ O₃, La₂ O₃, silica gels, clays andzeoliths. A suitable solid carrier material is also activated carbon.Further, the solid carrier material may also be formed by polysiloxaneswhich are obtainable by condensing compounds of formula I by themselvesor together with alkoxysilanes. Preferred carrier materials are silicagels, aerosils, alumina, titanium oxide and mixtures thereof. Exemplaryof a suitable glass carrier material is commercially availablecontrolled pore glass.

The modified carrier material of this invention can be obtained byreacting a solid carrier material which contains diphosphines fixed onthe surface thereof and has the formula ##STR5## wherein R₁, R₂, R₃, R₄,X, T, m, n and r are as previously defined, with a metal compound offormula [M(Y)Z]₂ or M(Y)₂.sup.⊕ A.sup.⊖, wherein M, Y, Z and A.sup.⊖ areas previously defined.

The reaction is preferably carried out in an inert gas atmosphere, asunder argon, and conveniently in the temperature range from 0° to 40°C., preferably at room temperature. The concurrent use of a solvent ormixture of solvents is advantageous, conveniently selected from thegroup consisting of hydrocarbons (benzene, toluene, xylene), halogenatedhydrocarbons (methylene chloride, chloroform, carbon tetrachloride,chlorobenzene), alkanols (methanol, ethanol, ethylene glycol monomethylether), and ethers (diethyl ether, dibutyl ether, ethylene glycoldimethyl ether) or mixtures thereof.

The novel modified material is also obtainable by direct reaction of ahydroxyl group containing solid material, a compound of formula I and ametal compound of formulae [M(Y)Z]₂ or M(Y)₂.sup.⊕ A.sup.⊖. The reactioncan be carried out stepwise by first adding a solution of the compoundof formula I to the solid material, followed by the addition of asolution of the metal compound, or by first dissolving the compound offormula I and the metal compound in a solvent and adding this solutionto the solid material. The reaction conditions may be those describedpreviously or hereinafter in connection with the preparation of thematerial of formula V. The novel modified material can be isolated byfiltration and purified by washing with an alkanol and dried undervacuum.

The novel modified material can also be prepared in situ prior tohydrogenation and then used direct as hydrogenation catalyst.

The invention further relates to the solid material of formula V. It canbe prepared by reacting compounds of formula I with a hydroxyl groupcontaining carrier material, advantageously in an inert gas atmosphere,as under argon, and in the temperature range from 40° to 180° C. Theprocedure preferably comprises charging the solid material to a reactor,adding a solution of the compound of formula I, and stirring the mixtureat elevated temperature, conveniently in the range from 50° to 110° C.Suitable solvents are those mentioned above. The product is isolatedeither by decantation or filtration. The residue can be purified bywashing with an alkanol and is then dried under a high vacuum.

The novel modified material is preeminently suitable for use asheterogeneous catalyst for the enantioselective hydrogenation ofcompounds containing prochiral carbon double bonds and carbon/heteroatom double bonds, typically compounds which contain a group selectedfrom C═C, C═N, C═O, C═C--N and C═C--O (q.v. K. E. Konig, TheApplicability of Asymmetric Homogeneous Catalysis, in James D. Morrison(ed.), Asymmetric Synthesis, Vol. 5, Academic Press, 1985). Examples ofsuch compounds are prochiral imines and ketones. The novel catalysts canbe separated almsot completely from the reaction mixture after thereaction in simple manner, as by decantation or filtration, andsubsequently reused. Compared with other known homogeneous catalysts,there is no or only a minor loss of activity which if desired, can becompensated for by adding minor amounts of fresh catalyst. Furthermore,selectivities (optical yields) are obtained comparable to those ofhomogeneous catalysts. In the hydrogenation of N-arylketimines withnovel iridium catalysts, it has surprisingly been found that, along withcomparable selectivities, the novel catalysts even exhibit a highercatalytic activity and a substantially lower deactivation than thehomogeneous iridium catalysts disclosed in EP-A-0 256 982 and EP-A-0 301457.

In another of its aspects, the invention relates to the use of the solidcarrier material of formulae IV or IVa as heterogeneous catalyst for theasymmetrical hydrogenation of prochiral compounds containing carbondouble bonds or carbon/hetero atom double bonds, especially thosecontaining a C═C, C═N, C═O, C═C--N or C═C--O group. The use forhydrogenating unsymmetrical carbon double bonds, ketimines and ketonesis preferred. It is also preferred to use the novel solid carriermaterial of formulae IV or IVa obtained in the form of the iridiumcatalyst for hydrogenating prochiral N-arylketimines to optically activesecondary amines. The novel solid carrier material of formulae IV or IVaobtained in the form of the rhodium catalyst is preferably used forhydrogenating carbon double bonds, as for example prochiral carbondouble bonds.

In yet another of its aspects, the invention relates to a process forthe asymmetrical hydrogenation of compounds containing carbon doublebonds or carbon/hetero atom double bonds, which comprises hydrogenatingsaid compounds in the temperature range from -20° to +80° C. and under ahydrogen pressure of 10⁵ to 10⁷ Pa, in the presence of catalytic amountsof a solid carrier material of formula IV or IVa.

Preferred compounds have already been mentioned. Unsymmetrical ketiminesand ketones are known. Suitable N-arylketimines are disclosed, forexample, in EP-A-0 256 982. N-Aliphatic ketimines are disclosed, forexample, in EP-A-0 301 457. Imines can be prepared from thecorresponding unsymmetrical ketones, which are known and in some casescommercially available or obtainable by known processes. Suitableunsubstituted or substituted alkenes are described in the publication byK. E. Konig cited above.

The process is preferably carried out in the temperature range from -20°to +50° C. and preferably under a hydrogen pressure of 1·10⁵ to 6·10⁶Pa.

The amount of catalyst will preferably be chosen such that the molarratio of compound to be hydrogenated to active catalyst component fixedon the solid carrier material is preferably from 2000 to 40, mostpreferably 800 to 50.

A preferred process comprises additionally using an ammonium or alkalimetal chloride, bromide or iodide, especially when using novel iridiumcatalysts. The amount may be from 0.1 to 100, preferably 1 to 50 and,most preferably, 2 to 20, equivalents, based on the active catalystcomponent fixed on the solid carrier material. The addition of iodidesis preferred. Ammonium is preferably tetraalkylammonium containing 1 to6 carbon atoms in the alkyl moieties. The preferred alkali metal islithium, sodium or potassium.

The hydrogenation can be carried out without or in the presence ofsolvents. Suitable solvents, which may be used alone or in admixture,are typically: aliphatic and aromatic hydrocarbons (pentane, hexane,cyclohexane, methycyclohexane, benzene, toluene, xylene); alcohols(methanol, propanol, butanol, ethylene glycol monomethyl ether); ethers(diethyl ethers, diethylene glycol dimethyl ether, tetrahydrofuran,dioxane); halogenated hydrocarbons (methylene chloride, chloroform,1,1,2,2-tetrachloroethane, chlorobenzene); carboxylates and lactones(ethyl acetate, butyrolactone, valerolactone); N-substituted acid amidesand lactams (dimethyl formamide, N-methylpyrrolidine). Mixtures of anaromatic hydrocarbon and an alcohol, for example toluene/ethanol orbenzene/methanol are advantageous.

By means of the inventive hydrogenation process it is possible to obtainoptically pure compounds which are useful intermediates for thesynthesis of biologically active compounds, especially in thepharmaceutical and agrochemical sectors. Thus, for example, herbicidallyactive 5-imidazolecarboxylic acid derivatives which can be used for weedcontrol (EP-A-0 207 563) can be obtained from amines, especiallyN-carbalkoxymethylamines. The optically pure α-aminocarboxylic acidesters are suitable for peptide syntheses.

The following Examples illustrate the invention in more detail. Thereactions are carried out under argon. The NMR spectra are recorded witha 250 Mhz spectrophotometer.

PREPARATION OF THE STARTING MATERIALS EXAMPLE A1:(2S,4S)-N-[(1'-Triethoxysilylprop-3'-yl)aminocarbonyl]-2-(diphenyl)phosphinmethyl-4-diphenylphosphine-pyrrolidine.

505 mg (1.11 mmol) of(2S,4S)-2-(diphenylphosphine)-4-(diphenylphosphine)methylpyrrolidine(PPM) are dissolved in 10 ml of toluene in a round flask. Then 306 mg(1.2 mmol) of 1-triethoxysilyl-3-isocyanatopropane are added dropwiseand the solution is stirred for 60 minutes at 44° C. After cooling, thesolvent is removed on a rotary evaporator at 40° C. and the residue iskept for 3 hours under a high vacuum, giving 870 mg of a slightlyyellowish viscous oil which still contains some toluene. The crudeproduct can be used direct in the subsequent reactions. Purification isby column chromatography (Merck 60 silica gel, elution with diethylether). Mass spectrum: 700 (M⁺). ³¹ P-NMR (CDCl₃): -8.79 (s), -22.90(s). ¹ H-NMR (CDCl₃): 4.08 (t, 1H, NHCO).

EXAMPLE A2:(2S,4S)-N-[(1'-Triethoxysilylundec-11'-yl)aminocarbonyl]-2-(diphenylphosphine)methyl-4-diphenylphosphine-pyrrolidine.

To a solution of 505 mg (1.11 mmol) of PPM in 5 ml of dry methylenechloride are added 420 mg (1.17 mmol) of1-triethoxysilyl-11-isocyanato-undecane, and the mixture is stirred for20 hours at room temperature. The solution is charged direct to a column(Merck 60 silica gel) and chromatographed (elution with diethyl ether).The fractions are concentrated at 40° C. under vacuum on a rotaryevaporater and dried under a high vaccum, giving 860 mg (95%) of acolourless oil. Mass spectrum: 812 (M⁺). ³¹ P-NMR (CDCl₃): -8.78(s),-22.92(s).

EXAMPLE A3:(3R,4R)-N-[(1'-Triethoxysilylprop-3'-yl)aminocarbonyl]-3,4-bis(diphenylphosphine)-pyrrolidine.

A solution of 494 mg (2 mmol) of 1-triethoxysilyl-3-isocyanatopropane in5 ml of methylene chloride is added dropwise to a solution of 790 mg(1.8 mmol) of (3R,4R)-3,4-bis(diphenylphosphine)-pyrrolidine in 5 ml ofdry methylene chloride, and the mixture is stirred for 20 hours at roomtemperature. The solvent is then removed under vacuum on a rotaryevaporator and the residue is dried under a high vacuum. The viscous oilis stirred in 10 ml of hexane and the white precipitate is isolated byfiltration, washed with hexane and dried under a high vacuum. Yield:95%. ³¹ P-NMR (CDCl₃): -11.7 (s). ¹ H-NMR (CDCl₃): 3.16 (m, 2H, CH₂ NH).

EXAMPLE A4:(3R,4R)-N-[(1'-Triethoxysilylundec-11'-yl)aminocarbonyl]-3,4-bis(diphenylphosphine)-pyrrolidine.

870 mg (2.42 mmol) of 1-triethoxysilyl-11-isocyanato-undecane are addeddropwise to a solution of 1011 mg (2.3 mmol) of(3R,4R)-bis(diphenylphosphine)pyrrolidine in 5 ml of dry methylenechloride, nd the mixture is stirred for 20 hours at room temperature.The mixtures is then charged direct to a column (Merck 60 silica gel)and chromatographed (elution with diethyl ether). The solvent of thefractions is removed under vacuum at 40° C. on a rotary evaporator andthe residue is dried under a high vacuum, giving 1.57 g (79%) of acolourless oil. ³¹ P-NMR (CDCl₃): -11.66 (s). ¹ H-NMR (CDCl₃): 3.16 (m,2H, CH₂ NH).

B) PREPARATION OF CARRIER MATERIALS WITH FIXED LIGANDS EXAMPLE B1Compound A1 on silica gel.

With stirring, 2.5 g of silica gel (Merck 100) are dried at 130° C.under a high vacuum and then cooled to room temperature under argon.Then a solution of 260 mg of compound A1 in 15 ml of dry, degassedtoluene are added and the mixture is slowly stirred for 5.5 hours at 70°C.. After cooling, the supernatant solution is removed by vacuumfiltration from the silica gel, which is washed 5 times with degassedmethanol and subsequently dried at 30° C. under a high vacuum. Elementalanalysis shows a phosphorus content of 0.69%, corresponding to 111 μmolof fixed compound A1 per g of silica gel.

EXAMPLE B2 Compound A3 on silica gel.

With stirring, 3 g of silica gel (Merck 100) are dried at 130° C. undera high vacuum and then cooled to room temperature under argon. Then asolution of 295 mg of compound A3 in 19 ml of dry toluene is added andthe mixture is slowly stirred for 4 hours at 70° C. After cooling, thesupernatant solution is removed by vacuum filtration from the silicagel, which is washed with 5×20 ml of degassed methanol and subsequentlydried under a high vacuum. Elemental analysis shows a phosphorus contentof 0.55%, corresponding to 88.7 μmol of fixed compound A3 per g ofsilica gel.

EXAMPLE B3 Compound A4 on silica gel.

The procedure of Example B2 is repeated, but using compound A4.Elemental analysis shows a phosphorus content of 0.3%, corresponding to48. μmol of fixed compound A4 per g of silica gel.

EXAMPLE B4 Compound A1 on silica gel (high ligand loading).

With stirring, 1.5 g of silica gel (Merck 100) are dried at 130° C.under a high vacuum in a 50 ml glass tube reactor and then cooled toroom temperature under argon. Then a solution of 407 mg (0.581 mmol) ofcompound A1 in 7.5 ml of dry, degassed toluene are added and the mixtureis slowly stirred for 16 hours at 90° C. After cooling, the supernatantsolution is removed by vacuum filtration from the silica gel, which iswashed 5 times with degassed methanol and subsequently dried at 30° C.under a high vacuum. Elemental analysis shows a phosphorus content of1.27%, corresponding to 204 μmol of fixed compound A1 per g of silicagel.

C) PREPARATION OF CATALYSTS EXAMPLE C1 Rhodium catalyst with compound A1on aerosil.

In a round flask, 0.7 g of aerosil (MOX 170, Degussa) is repeatedlydegassed with argon under a high vacuum and placed under an argonatmosphere. In a second flask, 58.9 mg (0.084 mmol) of compound A1 and17.3 mg (0.035 mmol) of [Rh(cyclooctadiene)Cl]₂ are repeatedly degassedwith argon under a high vacuum and then dissolved in 20 ml of drytoluene under argon. The solution is added to the aerosil and themixture is slowly stirred for 5.5 hours at 60° C.. After cooling, themixture is centrifuged and the supernatant solution is stripped off. Theresidue is washed with 5×8 ml of methanol and then dried under a highvacuum at 30° C. Elemental analysis shows a phosphorus content of 0.75%and a rhodium content of 0.95%, corresponding to 121 μmol of fixedcompound A1 per g of aerosil and 92 μmol of rhodium complex per g ofaerosil.

EXAMPLE C2 Rhodium catalyst with compound A3 on silica gel.

With stirring, 1.3 g of silica gel (Merck 100) are dried at 130° C. for3 hours under a high vacuum in a round flask, then placed under argonand cooled to room temperature. In a second round flask, 118 mg (0.172mmol) of compound A3 and 54 mg (0.143 mmol) of Rh(norbornadiend)₂ BF₄are degassed repeatedly with argon under a high vacuum and dissolved in8 ml of dry toluene and 1 ml of dry methanol. The solution is added tosilica gel and the mixture is slowly stirred for 4.5 hours at 55° C..After cooling and settling out, the supernatant solution is stripped offand the residue is washed with 5×5 ml of methanol and then dried at 30°C. under a high vacuum. Elemental analysis shows a phosphorus content of0.75% and a rhodium content of 0.95%, corresponding to 121 μmol of fixedcompound A3 per g of aerosil and 92 μmol of rhodium complex per g ofsilica gel.

EXAMPLE C3 Rhodium catalyst with compound A3 on silica gel.

The procedure of Example C2 is repeated, but using only 8 ml of methanolas solvent. Elemental analysis shows a phosphorus content of 0.33% and arhodium content of 0.45%, corresponding to 53 μmol of fixed compound A3per g of aerosil and 44 μmol of rhodium complex per g of aerosil.

D) USE EXAMPLES EXAMPLE D1 Hydrogenation of methyl(Z)-acetamidocinnamate with rhodium catalyst C2.

44.4 mg (4.1 μmol) of rhodium complex C2 are weighed into a glassreactor and a solution of 4.1 mmol of methyl (Z)-acetamidocinnamate in13.5 ml of methanol is added under argon. The mixture is introducedunder argon pressure into a 50 ml steel autoclave with the aid of acapillary. After flushing with hydrogen and reducing the pressure threetimes, the hydrogen pressure is set to 5.8.10⁶ Pa. The hydrogenation isinitiated by activating the stirrer. The conversion is determined by thefall in pressure and analysed by gas chromatography. The conversion is100% after 85 minutes, and the enantiomer excess (ee) is 85.8%.

The reaction solution is drawn off under argon with a syringe and via amembrane. The catalyst on the membrane is thereafter returned to theautoclave with a fresh reaction solution (4.1 mmol of methyl(Z)-acetamidocinnamate in 13.5 ml of methanol) and hydrogenation iscarried out under the same conditions. The conversion is 100% after 210minutes, ee 84.3%.

EXAMPLE D2 Hydrogenation of methyl (Z)-acetamidocinnamate with rhodiumcatalyst C3.

The procedure of Example D1 is repeated, using 32 μmol of rhodiumcatalyst C3 and 3.25 mmol of methyl (Z)-acetamidocinnamate in 11 ml ofmethanol. The conversion is 100% after 60 minutes, ee 86.6%.

The catalyst is reused as in D1: The conversion is 100% after 90minutes, ee 86.7%.

EXAMPLE D3 Preparation of the catalyst in situ.

In a round flask, 169 mg (18.8 μmol) of carrier material of Example B1are dissolved in 5.3 l of tetrahydrofuran. In another round flask, 13.4μmol of Rh(norbornadiene)₂ BF₄ are dissolved in 2.7 ml of degassedmethanol. Both mixtures are combined and stirred until the solution isdecolourised. Then a solution of 2.69 mmol of methyl(Z)-acetamidocinnamate in 16 ml of methanol is added to this mixture.The mixture is evacuated and flushed three times with hydrogen, and thehydrogen pressure is set to 10⁵ Pa. The batch is then stirredvigorously. The conversion is 99.9% after 32 minutes, ee 93.5%.

Reuse of the catalyst: The reaction solution is stripped off from thecatalyst and then a solution of 2.69 mmol of methyl(Z)-acetamidocinnamate is added. The hydrogen pressure is set to 10⁵ Paand the batch is stirred vigorously. The conversion is 100% after 16minutes, ee 94.8%.

EXAMPLE D4 In situ preparation of a catalyst.

150 mg (17 μmol) of the carrier material of Example B1 are charged underargon to a round falsk and, in a second round flask, 6.8 μmol of[Rh(cyclooctadiene)Cl]₂ are dissolved under argon in 2.5 ml of tolueneand the solution is then added dropwise to the first flask. Afterwards,the mixture is stirred until the solution is decolourised and then asolution of 2.72 mmol of methyl (Z)-acetamidocinnamate in 22 ml ofethanol is added dropwise. The mixture is evacuated and then flushedthree times with hydrogen, and the hydrogen pressure is set to 10⁵ Pa.The batch is then stirred vigorously. The conversion is 99.6% after 75minutes, ee 85%.

Reuse of the catalyst: The reaction solution is stripped off from thecatalyst and then a solution of 2.72 mmol of methyl(Z)-acetamidocinnamate is added. Hydrogenation is carried out aspreviously under a hydrogen pressure of 10⁵ Pa. The conversion is 99%after 32 minutes, ee 82.5%.

EXAMPLE D5 In situ preparation of the catalyst

53.1 mg (4.7 μmol) of the carrier material of Example B2 are weighedinto a round flask under argon and, in a second round flask, 3.9 μmol of[Rh(norbornadiene)₂ ]BF₄ are dissolved under argon in 1.5 ml of methanoland the solution is added dropwise to the first flask. The batch is thenstirred to decolourise the solution. A solution of 4 mmol of methyl(Z)-acetamidocinnamate in 12 ml of methanol is added to this solutionand the mixture is introduced under pressure into a 50 ml steelautoclave. The pressure is released and the mixture is flushed threetimes with hydrogen under a pressure of 5·10⁶ Pa, and finally thehydrogen pressure is set to 5.8·10⁶ Pa. The batch is subsequentlyvigorously stirred. The conversion is 100% after 40 minutes, ee 88%.Reuse of the catalyst: The reaction solution is drawn off via a membraneand the catalyst is returned to the autoclave with a solution of of 4mmol of methyl (Z)-acetamidocinnamate in 12 ml of methanol.Hydrogenation is carried out as described above. The conversion is 100%after 78 minutzes, ee 87.3%.

EXAMPLE D6 Preparation of the catalyst in situ.

The procedure of Example D4 is repeated, but using 2.9 μmol of thecarrier material of Example B3, 2.4 μmol of [Rh(norbornadiene)₂ ]BF₄ in0.9 ml of methanol and 4.8 mmol of methyl (Z)-acetamidocinnamate in 14.3ml of methanol. The conmversion after 95 minutes is 100%, ee 85.5%.

Reuse of the catalyst: The procedure of Example D4 is repeated, butusing 5.17 mmol of methyl (Z)-acetamidocinnamate in 15.5 ml of methanol.The conversion after 230 minutes is 100%, ee 88%.

In Examples D1 to D6 the conversion is determined by the drop inpressure and by gas chromatography column SE 54, 15 m). The enantiomerexcess (ee) is determined by gas chromatography (column Chirasil-1-Val,50 m).

EXAMPLE D7 Hydrogenation with iridium catalyst.

10.5 μmol of [Ir(cyclooctadiene)Cl]₂, 26.3 μmol of the carrier materialof Example B1 and 42 μmol of tetra-n-butylammonium iodide are charged toa round flask together with 6.2 ml of methanol and 6.2 ml of benzeneunder argon, and the mixture is stirred until the solution isdecolourised. Then a solution of 2.01 g (10.5 mmol) ofN-(2,6-dimethylphen-1-yl)methoxymethylmethylketimine is added dropwiseand the mixture is introduced under pressure into a 50 ml steelautoclave. The mixture is evacuated and flushed with hydrogen threetimes, and the hydrogen pressure is finally set to 4·10⁶ Pa. The batchis stirred at 30° C. and the course of the hydrogenation is followed byobserving the drop in pressure. The conversion is analysed by gaschromatography. The catalyst is isolated by filtration and the solventis stripped from the reaction mixture under pressure on a rotaryevaporator. The crude product is purified by flash chromatography(silica gel, hexane/ethyl acetate 1:1), and the enantiomer excess isdetermined by polarimetry (rotation of the (S)-enantiomer [α]₃₆₅ at 20°C.-130.5°, c=3 in hexane). The conversion after 19 hours is 96.5%, ee62.7%.

Reuse of the catalyst: The supernatant solution is stripped from thecatalyst, the same amount of ketimine as before is added and the sameprocedure is carried out. The conversion after 35 hours is 100%, ee61.1%.

EXAMPLE D8 Hydrogenation with iridium catalyst.

The procedure of Example D7 is repeated, but using the carrier materialof Example B2 and setting the hydrogenation pressure to 9·10⁶ Pa. Theconversion after 6 hours is 100%, ee 29.1%.

EXAMPLE D9 Hydrogenation with rhodium catalyst prepared in situ.

78.6 mg (0.016 μmol) of the carrier material of Example B4 are weighedinto a round flask under argon and, in a second round flask, 0.0125 mmolof [Rh(cyclooctadiene)₂ ]BF₄ are dissolved under argon in 1 ml of MeOHand the solution is added dropwise to the first flask. The batch is thenstirred to decolourise the solution. To this mixture is added a solutionof 2.5 mmol of methyl (Z)-acetamidocinnamate in 17.5 ml of methanol and4 ml of tetrahydrofuran. The mixture is evacuated and flushed threetimes with hydrogen, and the hydrogen pressure is set to 10⁵ Pa. Thebatch is then vigorously stirred. The conversion is 100% after 28minutes, ee 91.9%. Reuse of the catalyst: The reaction solution isstripped off from the catalyst. Then a solution of 2.5 mmol of methyl(Z)-acetamidocinnamate in 17.5 ml of methanol and 4 ml oftetrahydrofuran is added. The mixture is evacuated once more three timesand flushed with hydrogen, and the hydrogen pressure is set to 10⁵ Pa.The batch is then vigorously stirred. The conversion is 100% after 15minutes, ee 93.1%.

What is claimed is:
 1. A compound of formula I ##STR6## wherein thegroups (R₁)₂ P(CH₂)_(m) and n are in o- or m-position to each other andthe substituents R₁ are identical or different radicals, m and n areeach independently of the other 0 or 1, R₁ is linear or branched C₁ -C₁₂alkyl, unsubstituted C₅ -C₆ cycloalkyl or C₅ -C₆ cycloalkyl which issubstituted by C₁ -C₄ alkyl or C₁ -C₄ alkoxy, or is phenyl or benzyl, orboth substituents R₁ in a group (R₁)₂ P together are o,o'-diphenylene,--R₂ --X-- is a bond or --(C_(x) H_(2x) --O)_(y) --, or X-- is O-- andR₂ is C₁ -C₆ alkylene, x is an integer from 2 to 6 and y is an integerfrom 2 to 6, R₃ is C₂ -C₁₈ alkylene, phenylene or benzylene, and R₄ isC₁ -C₆ alkyl or phenyl.
 2. A compound of formula I according to claim 1,wherein the sum of m+n is 0 or
 1. 3. A compound of formula I accordingto claim 1, wherein R₁ is phenyl.
 4. A compound of formula I accordingto claim 1, wherein --R₂ --X-- is a bond.
 5. A compound of formula Iaccording to claim 1, wherein R₃ is linear or branched C₂ -C₁₂-alkylene.
 6. A compound of formula I according to claim 1, wherein R₄is methyl or ethyl.
 7. A compound according to claim 1 which is in theform of the optically active isomers, with respect to the position ofthe phosphine(methyl) groups.
 8. A compound of formula I according toclaim 1, wherein R₁ is phenyl and --R₂ X-- is a bond, R₃ is1,3-propylene and R₄ is methyl or ethyl, and m is 1 and n is 0, and thegroups (R₁)₂ P- and (R₁)₂ PCH₂ - are in m-position, or m and n are each0 and the groups (R₁)₂ P- are in o-position.
 9. A solid carrier materialwhich contains a diphosphine rhodium or iridium complex fixed on thesurface thereof, which carrier material has the formula IV or IVa##STR7## wherein Y denotes two monoolefin ligands or a diene ligand, Mis Ir(I) or Rh(I), Z is --Cl, --Br or --I, A.sup.⊖ is the anion of anoxyacid or complex acid, T is a solid carrier material, r is 0, 1 or 2,m and n are m and n are each independently of the other 0 or 1, R₁ islinear or branched C₁ -C₁₂ alkyl, unsubstituted C₅ -C₆ cycloalkyl or C₅-C₆ cycloalkyl which is substituted by C₁ -C₄ alkyl or C₁ -C₄ alkoxy, oris phenyl or benzyl, or both substituents R₁ in a group (R₁)₂ P togetherare o,o'-diphenylene, --R₂ --X-- is a bond or --(C_(x) H_(2x) --O)_(y)--, or X-- is O-- and R₂ is C₁ -C₆ alkylene, x is an integer from 2 to 6and y is an integer from 2 to 6, R₃ is C₂ -C₁₈ alkylene, phenylene orbenzylene, and R₄ is C₁ -C₆ alkyl or phenyl.
 10. A carrier materialaccording to claim 9, wherein Y in formulae IV and IVa is 1,5-hexadiene,1,5-cycloactadiene or norbornadiene.
 11. A carrier material according toclaim 9, wherein Z in formula IV is --Cl or --Br.
 12. A carrier materialaccording to claim 9, wherein A.sup.⊖ in formula IVa is ClO₄.sup.⊖, CF₃SO₃.sup.⊖, BF₄.sup.⊖, B(phenyl)₄.sup.⊖, PF₆.sup.⊖, SbCl₆.sup.⊖ ,AsF₆.sup.⊖ or SbF₆.sup.⊖.
 13. A carrier material according to claim 9which is a silicate, a semimetal or a metal oxide.
 14. A carriermaterial according to claim 13 which is a powder.
 15. A carrier materialaccording to claim 13, which is a silica gel, an aerosil, an alumina, atitanium oxide or a mixture thereof.
 16. A process for the preparationof a solid carrier material of formula IV or IVa according to claim 10,which comprises reacting a solid carrier material which containsdiphosphines fixed on the surface thereof and has the formula ##STR8##wherein R₁, R₂, R₃, R₄, X, T, m, n and r are as defined in claim 9, witha metal compound of formula [M(Y)Z]₂ or M(Y)₂.sup.⊕ A.sup.⊖, wherein M,Y, Z and A.sup.⊖ are as defined in claim
 10. 17. A solid modifiedcarrier material of formula V ##STR9## wherein R₁, R₂, R₃, R₄, X, T, m,n and r are as defined in claim 9.